14 DAY TRIAL // Cinnamon, a Linux desktop environment based on GNOME 3 which provides new features while preserving a more conventional approach, has just received an update that should make the Unity problem go away.
Users of Ubuntu 13.04 and Ubuntu 13.10 have noticed that they aren't able to login back in Unity after installing the new Cinnamon 2.0. Apparently, this has something to do with Upstart.
A very astute reader has shown us a couple of new commits that have been pushed into the stable branch that should take care of the problem. According to the changelogs, the Upstart files which caused the Unity crash have been removed.
The update is not yet available in the PPA, so don't rush to install Cinnamon just yet. It's likely that the next update, Cinnamon 2.0.7, will incorporate the necessary fixes.